Most planetary systems contain worlds larger than Earth but smaller than Neptune, and the low-density planets around one ...

The newly identified cluster of Kuiper Belt objects lies about 4 billion miles from the Sun, offering fresh clues about how ...

TEMPE, Ariz. a Quick: What’s the order of the planets in the solar system? Need a little help? Maybe the following mnemonic rings a bell: “My Very Educated Mother Just Served Up Nine Pizzas.” It’s ...

Super-Earths and sub-Neptunes, planets with sizes between Earth and Neptune, constitute approximately one-third of known exoplanets but are absent in our solar system. Their prevalence elsewhere and ...

Stars and planets are inextricably linked. They form together and stars shape the fate of planets. Stars create the dusty ...

UNDATED (WKRC) - Astronomers recently made an important discovery when they found a rare "in-sync" solar system with six planets all moving in one big grand harmony, completely untouched by outside ...

Something is throwing icy bodies past Neptune, and scientists have an interesting idea about what it might be. When you purchase through links on our site, we may earn an affiliate commission. Here’s ...

So far, humanity has yet to find its first "exomoon"—a moon orbiting a planet outside of the solar system. But that hasn't ...

Astronomers using planet-hunting satellites have discovered a rare solar system with six planets moving completely in sync with one another, as if they were untouched by any outside force since being ...

The International Astronomical Union (IAU) defines a planet as a celestial body orbiting the Sun, possessing sufficient mass for a nearly spherical shape, and having cleared its orbital neighborhood ...